Conventionally, for example, Patent Literature 1 and Patent Literature 2 disclose a structure which withstands blasts or impacts caused by explosive objects such as landmines or improvised explosive devices against a bottom surface of a vehicle. Patent Literature 1 discloses an armored vehicle having a V-shaped bottom surface. Further, Patent Literature 2 discloses a configuration in which a foamed resin (polyurethane foam) is used for a portion which is a V-shaped bottom surface.